U.S. patent number 7,568,536 [Application Number 11/524,478] was granted by the patent office on 2009-08-04 for omni-directional robot cleaner.
This patent grant is currently assigned to Industrial Technology Research Institute. Invention is credited to Fang Chang, Shou-Ren Chen, Yu-Lun Ho, Wei-Han Wang, Hung-Hsiu Yu.
United States Patent |
7,568,536 |
Yu , et al. |
August 4, 2009 |
Omni-directional robot cleaner
Abstract
An omni-directional robot cleaner, composed of a platform and a
plurality of driving units for driving and controlling the movement
of the platform, in which the platform further comprises: a sensing
unit, for obstacle detection; a cleaning unit, for collecting and
removing dust and dirt; a processing unit, capable of receiving
signals transmitted from the sensing unit while planning and
mapping a travel path accordingly; and a power unit, for providing
power to the omni-directional robot cleaner while managing the
same. Moreover, each driving unit of the plural driving units is
comprised of an omni-directional wheel and an actuator for driving
the corresponding omni-directional wheel to rotate
omni-directionally, by which the platform is enabled to move
continuously while changing its moving direction simultaneously so
as to free the robotic cleaner from the shortcomings of those
conventional autonomous cleaner, such as poor maneuverability, poor
mobility and insufficient degree-of-freedom regarding to the
driving of the cleaner. Therefore, not only the operation mobility
of the robotic cleaner is enhanced, but also the moving agility of
the same is greatly improved.
Inventors: |
Yu; Hung-Hsiu (Changhua County,
TW), Chen; Shou-Ren (Taichung, TW), Ho;
Yu-Lun (Taipei County, TW), Wang; Wei-Han (Taipei
County, TW), Chang; Fang (Hsinchu, TW) |
Assignee: |
Industrial Technology Research
Institute (Hsinchu, TW)
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Family
ID: |
38748487 |
Appl.
No.: |
11/524,478 |
Filed: |
September 21, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070272463 A1 |
Nov 29, 2007 |
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Foreign Application Priority Data
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May 23, 2006 [TW] |
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95118246 A |
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Current U.S.
Class: |
180/6.2; 15/319;
180/168; 180/169; 318/567; 318/568.12; 318/587; 700/245 |
Current CPC
Class: |
B60T
7/22 (20130101) |
Current International
Class: |
B62D
6/00 (20060101) |
Field of
Search: |
;180/6.2,168,169
;700/245 ;318/568.12,567,587 ;15/319 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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4-221524 |
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Aug 1992 |
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JP |
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2003-305671 |
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Oct 2003 |
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JP |
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346810 |
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Dec 1998 |
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TW |
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I 262777 |
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Oct 2006 |
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TW |
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Primary Examiner: Morris; Lesley D
Assistant Examiner: Arce; Marlon A
Attorney, Agent or Firm: Birch, Stewart, Kolasch &
Birch, LLP
Claims
What is claimed is:
1. An omni-directional robot cleaner, comprising: a sensing unit,
for obstacle detection; a cleaning unit, for collecting and
removing dust and dirt; a processing unit, capable of receiving
signals transmitted from the sensing unit while planning and
mapping a travel path accordingly; a power unit, for providing
power to the omni-directional robot cleaner while managing the
same; a platform, for supporting the aforesaid units; and at least
three driving units are configured in the omni-directional robot
cleaner, for driving and controlling the movement of the platform,
each being composed of an omni-directional wheel and an actuator,
wherein said three omni-directional wheels can be identified as the
first omni-directional wheel, the second omni-directional wheel and
the third omni-directional wheel respectively, and wherein when the
first omni-directional wheel is stopped without rotating while the
second omni-directional wheel is rotating clockwisely and the third
omni-directional wheel is rotating counterclockwisely, by which the
platform is driven to in the direction specified by a first
direction, when the first omni-directional wheel is stopped without
rotating while the second omni-directional wheel is rotating
counterclockwisely and the third omni-directional wheel is rotating
clockwisely, the platform is driven to in the direction specified
by a second direction that is the opposite direction of the first
direction, when the third omni-directional wheel is stopped without
rotating while the first omni-directional wheel is rotating
clockwisely and the second omni-directional wheel is rotating
counterclockwisely, by which the platform is driven to in the
direction specified by a third direction, when the third
omni-directional wheel is stopped without rotating while the first
omni-directional wheel is rotating counterclockwisely and the
second omni-directional wheel is rotating clockwisely, the platform
is driven to in the direction specified by a forth direction that
is the opposite direction of the third direction, and when the
second omni-directional wheel is stopped without rotating while the
third omni-directional wheel is rotating clockwisely and the first
omni-directional wheel is rotating counterclockwisely, by which the
platform is driven to in the direction specified by a fifth
direction, and when the second omni-directional wheel is stopped
without rotating while the first omni-directional wheel is rotating
counterclockwisely and the third omni-directional wheel is rotating
clockwisely, the platform is driven to in the direction specified
by a sixth direction that is the opposite direction of the fifth
direction, and when all the three omni-directional wheels are all
enabled to rotate counterclockwisely, the platform is driven to
rotate clockwisely without moving and when all the three
omni-directional wheels are all enabled to rotate clockwisely, the
platform is driven to rotate counterclockwisely without moving.
2. The omni-directional robot cleaner of claim 1, wherein all the
driving units configured in the omni-directional robot cleaner are
equiangularly spaced from each other.
3. The omni-directional robot cleaner of claim 1, wherein the
omni-directional wheels of the plural driving units are capable of
being enabled to rotate at the same speed.
4. The omni-directional robot cleaner of claim 1, wherein each
actuator is a motor.
5. The omni-directional robot cleaner of claim 1, wherein the
cleaning unit is a device selected from the group consisting of a
brush, a vacuuming apparatus, and the like.
Description
FIELD OF THE INVENTION
The present invention relates to an omni-directional robot cleaner,
and more particularly, to a novel autonomous mobile cleaner capable
of adopting a means of motion vector for defining its moving
position from an original position thereof and thus enabling the
same to update its motion vector at any time and instantly change
it moving direction accordingly, that the omni-directional robot
cleaner is able to move forward, backward, sideway in a random
direction as well as rotate in a continuous manner and this it is
free from the shortcomings of those conventional autonomous
cleaner, such as poor maneuverability, poor mobility and
insufficient degree-of-freedom regarding to the driving of the
cleaner. Therefore, not only the operation mobility of the robotic
cleaner is enhanced, but also the moving agility of the same is
greatly improved.
BACKGROUND OF THE INVENTION
Generally, a conventional autonomous mobile cleaner is carried to
move by a plurality of common wheels, driven to rotate by a motor.
Therefore, the conventional autonomous mobile cleaner can be driven
to turn by the rotational speed difference between those wheels as
the operating cleaner is running into obstacles like a wall or a
drop of stairs. It is known that the turning of a conventional
autonomous mobile cleaner carried by common wheels can be achieved
in the following fashions: (1) As the platform of the conventional
autonomous mobile cleaner is moved to a specific location and
stopped completely, the wheels are driven to turn toward a random
direction while not rotating, and then are driven to rotate after
the turn is complete. It is noted that, to turn a cease-rotating
wheel, a comparatively larger friction must be overcame, not to
mention that the aforesaid stop-turn-rotate fashion is time
consuming. Therefore, the aforesaid turning fashion will adversely
affect the moving efficiency of the autonomous mobile cleaner. (2)
As the platform is approaching a specific location, the rotating
wheel is driven to turn when the platform is still in motion. It is
noted that, to enable the platform to negotiate a turn while it is
still in motion, the motor control will be much complicated and the
resulting turn radius will be larger. Therefore, the aforesaid
turning fashion will cause the autonomous mobile cleaner to have
blind spot for cleaning. Hence, as the common wheel can not
instantly turn and move in a random direction, the moving
efficiency as well as the agility of the conventional autonomous
mobile cleaner are insufficient and unsatisfactory.
Please refer to FIG. 1, which shows a self-traveling type vacuum
cleaner disclosed in JP Pat. No. 4221524. The self-traveling type
vacuum cleaner 10 of FIG. 1 employs two driving wheels 12 and a
passive wheel as the moving mechanism for carrying the platform 11
to move, wherein the two driving wheels 12 are driven to rotate
respectively by the two independent motors 14. It is noted that the
moving mechanism of the vacuum cleaner 10 is the most popular among
conventional autonomous mobile cleaners. As the operating vacuum
cleaner 10 is running into an obstacle, the two motors 14 are
controlled to cause the generating of a speed difference between
the two rotating driving wheels 12 for enabling the platform 11 to
turn accordingly. As the platform 11 is turning, the passive wheel
13 will follow. However, the abovementioned moving mechanism still
suffer from the comparatively larger friction while turning, and it
is still not able to turn and move in a random direction instantly
at will. Therefore, the mobility of the abovementioned vacuum
cleaner 10 is not preferred.
Please refer to FIG. 2, which shows a spherical wheel vehicle
disclosed in JP Pat. No. 2003305671. The spherical wheel vehicle 20
of FIG. 2 employs more than two spherical driving wheels 22 as the
moving mechanism for carrying the platform 21 to move
omni-directionally. By the aforesaid moving mechanism, even if
colliding with an obstruction, it is safe because a wheel body of
each spherical driving wheel 22 merely turns inside the wheel shell
thereof, and a proceeding direction can be easily changed. However,
since the forgoing spherical driving wheels 22 can not be driven to
rotate directly by motors, a power transmission mechanism is
required for transmitting power from the motors to each spherical
driving wheels 22, by <which each spherical driving wheel 22 is
driven to rotate by friction. Therefore, some power can be lost
when the power transmission mechanism slips and thus the motion
accuracy of the spherical wheel vehicle 20 can be adversely
affected, not to mention that the overall driving mechanism of the
spherical wheel vehicle 20 will be much more complicated.
SUMMARY OF THE INVENTION
In view of the disadvantages of prior art, the primary object of
the present invention is to provide a novel omni-directional robot
cleaner, adopting a means of motion vector for defining its moving
position from an original position thereof and thus enabling the
same to update its motion vector at any time and instantly change
it moving direction accordingly, that the omni-directional robot
cleaner is able to move forward, backward, sideway in a random
direction as well as rotate in a continuous manner and this it is
free from the shortcomings of those conventional autonomous
cleaner, such as poor maneuverability, poor mobility and
insufficient degree-of-freedom regarding to the driving of the
cleaner. Therefore, not only the operation mobility of the robotic
cleaner is enhanced, but also the moving agility of the same is
greatly improved.
To achieve the above object, the present invention provide an
omni-directional robot cleaner, which comprises: a sensing unit,
for obstacle detection; a cleaning unit, for collecting and
removing dust and dirt; a processing unit, capable of receiving
signals transmitted from the sensing unit while planning and
mapping a travel path accordingly; a power unit, for providing
power to the omni-directional robot cleaner while managing the
same; a platform, for supporting the aforesaid units; and a
plurality of driving units, for driving and controlling the
movement of the platform, each being composed of an
omni-directional wheel and an actuator.
Preferably, there are at least three driving units configured in
the omni-directional robot cleaner, whereas all the driving units
configured in the omni-directional robot cleaner are equiangularly
spaced from each other.
Preferably, the omni-directional wheels of the plural driving units
are capable of being enabled to rotate at the same speed.
Preferably, the actuator can be a motor.
Preferably, the cleaning unit can be a device selected from the
group consisting of a brush, a vacuuming apparatus, and the
like.
Other aspects and advantages of the present invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a self-traveling type vacuum cleaner disclosed in JP
Pat. No. 4221524.
FIG. 2 shows a spherical wheel vehicle disclosed in JP Pat. No.
2003305671.
FIG. 3 shows the outlook of a conventional omni-directional wheel
set.
FIG. 4 is a schematic diagram showing an omni-directional robot
cleaner according to a preferred embodiment of the invention.
FIG. 5A to FIG. 5D shows various motions capable of being executed
by an omni-directional robot cleaner of the invention.
FIG. 6 shows an omni-directional robot cleaner operating in a
planetary motion mode according to the present invention.
FIG. 7 shows a travel path of an omni-directional robot cleaner
operating in a wall-following mode according to the present
invention.
FIG. 8 shows a travel of an omni-directional robot cleaner
operating in a column-following mode according to the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For your esteemed members of reviewing committee to further
understand and recognize the fulfilled functions and structural
characteristics of the invention, several preferable embodiments
cooperating with detailed description are presented as the
follows.
Please refer to FIG. 3, which shows the outlook of a conventional
omni-directional-wheel set. The omni-directional wheel 321 of FIG.
3 is unique because it rolls freely in two directions. In one
direction, it rolls like a normal wheel. It can also roll laterally
because of the smaller rollers spread about its circumference. The
omni-directional wheel 321, which has three free rollers 3212
mounted on the rim of the main wheel 3211 while being equiangularly
spaced, is characterized in that the main wheel 3211 can be driven
to rotate with respect to the central axis 3213 thereof while the
three free rollers 312 are rotating in a rotation direction
perpendicular to the rotation of the main wheel 3211. By conveying
a platform with the aforesaid omni-directional wheel, the platform
is enabled to move continuously and change its moving direction
simultaneously.
By the use of the omni-directional wheel similar to the aforesaid
omni-directional wheel 321, an improved robot cleaner is able to
move omni-directionally. Please refer to FIG. 4, which is a
schematic diagram showing an omni-directional robot cleaner
according to a preferred embodiment of the invention. The
omni-directional robot cleaner 30 has a platform having a plurality
of driving units 32 mounted on the circumference thereof while
being equiangularly spaced, in that each driving unit 32 is
composed of an omni-directional wheel 321 and an actuator 322 while
the actuator 322 can be a motor capable of independently
controlling the corresponding omni-directional wheel 321. In the
preferred embodiment shown in FIG. 4, three are three driving units
32. However, the amount of driving unit can be determined with
respect to the size of the platform 32 or the size of the
omni-directional wheel 321, and thus is not limited by the
embodiment of FIG. 4. Moreover, the platform 31 is comprised of a
sensing unit 311, a cleaning unit 312, a processing unit 313 and a
power unit 314, wherein the sensing unit 311 is used for detecting
obstruction in the ambient environment of the platform 31 so as to
obtain information such as the distance between the platform and a
detected obstacle, the shape of the detected obstacle, etc; the
cleaning unit 312 is used for or collecting and removing dust and
dirt, which can be a device selected from the group consisting of a
brush, a vacuuming apparatus, and the like; the processing unit 313
is capable of receiving signals transmitted from the sensing unit
311 while controlling the operation of each actuator 322
accordingly for planning and mapping a travel path; the power unit
313 is used for providing power to the omni-directional robot
cleaner 30 while managing the same. Thereby, an operating
omni-directional robot cleaner 30 is able to use the sensing unit
311 to detect obstacles existed in it ambient environment, and then
use the processing unit 313 to control the three actuators 322 to
drive the three omni-directional wheels 321 in respective according
to the detection of the sensing unit 311 for maneuvering the
omni-directional robot cleaner 30 around the detected obstacle by
changing its moving direction at random.
There can be various operation modes defined in an omni-directional
robot cleaner 30 of the invention, that are only a few thereof
being showing in FIG. 5A to FIG. 5D. For illustration, the platform
M shown in FIG. 5A to FIG. 5D has three omni-directional wheels W1,
W2, and W3, and all of the three omni-directional wheels W1, W2,
and W3 can be enabled to rotate at the same speed.
In FIG. 5A, the omni-directional wheel W1 is stopped without
rotating while the omni-directional wheel W2 is rotating
clockwisely and the omni-directional wheel W3 is rotating
counterclockwisely, by which the platform M is driven to in the
direction specified by the arrow A. Similarly, when the
omni-directional wheel W1 is stopped without rotating while the
omni-directional wheel W2 is rotating counterclockwisely and the
omni-directional wheel W3 is rotating clockwisely, the platform M
is driven to in the direction specified by the arrow A'.
In FIG. 5B, the omni-directional wheel W3 is stopped without
rotating while the omni-directional wheel W1 is rotating
clockwisely and the omni-directional wheel W2 is rotating
counterclockwisely, by which the platform M is driven to in the
direction specified by the arrow B. Similarly, when the
omni-directional wheel W3 is stopped without rotating while the
omni-directional wheel W1 is rotating counterclockwisely and the
omni-directional wheel W2 is rotating clockwisely, the platform M
is driven to in the direction specified by the arrow B'.
In FIG. 5C, the omni-directional wheel W2 is stopped without
rotating while the omni-directional wheel W3 is rotating
clockwisely and the omni-directional wheel W1 is rotating
counterclockwisely, by which the platform M is driven to in the
direction specified by the arrow C. Similarly, when the
omni-directional wheel W3 is stopped without rotating while the
omni-directional wheel W1 is rotating counterclockwisely and the
omni-directional wheel W3 is rotating clockwisely, the platform M
is driven to in the direction specified by the arrow C'.
In FIG. 5D, when the omni-directional wheels W1, W2, and W3 are all
enabled to rotate counterclockwisely, the platform M is driven to
rotate clockwisely without moving. Similarly, when the
omni-directional wheels W1, W2, and W3 are all enabled to rotate
clockwisely, the platform M is driven to rotate counterclockwisely
without moving.
In addition, by controlling the actuators 322, shown in FIG. 4, to
enable speed differences to be generated between the corresponding
omni-directional wheels W1, W2, and W3, the platform M can be
driven to move in any direction at will.
Moreover, please refer to FIG. 6 for an omni-directional robot
cleaner operating in a planetary motion mode according a further
embodiment of the present invention. As seen in FIG. 6, a planetary
motion of platform M is enabled by the cooperation of the three
omni-directional wheels W1, W2, and W3, i.e. the three
omni-directional wheels W1, W2, and W3 are controlled to enabled
the platform M to move linearly in a direction specified by the
arrow while rotating simultaneously. By the planetary motion, the
omni-directional robot cleaner can have comparatively wider
cleaning area comparing with those operating in other modes but
having the same amount of cleaning units N arranged therein. As
seen in FIG. 6, the cleaning unit N of the platform M operating in
other mode can only move forward linearly that is restrict to the
narrower cleaning area A2 while the cleaning unit N of the platform
M operating in planetary motion mode is rotating that a wider
cleaning area A1 is achieved.
Furthermore, please refer to FIG. 7 and FIG. 8, which show a travel
path of an omni-directional robot cleaner operating in a
wall-following mode and a travel path of that in a column-following
mode. In the wall-following mode shown in FIG. 7, different from
the zigzagging path combing rotating and straight-line moving
performed by those convention autonomous mobile cleaners in their
wall-following mode, the omni-directional robot cleaner in
wall-following mode is able to move while maintaining it contact to
a wall 40 as soon as the omni-directional robot cleaner comes into
contact with the wall 40, that is enabled by redefining motion
vector coordinate to drive the platform M. By the cooperation of
the wall-following mode and the planetary motion mode of FIG. 6,
dust and dirt deposited at the corner of the wall can be removed
completely. In addition, in the column-following mode shown in FIG.
8, the omni-directional robot cleaner is able to move while
maintaining it contact to and circling a column 50 as soon as the
omni-directional robot cleaner comes into contact with the column
50, that is enabled by redefining motion vector coordinate to drive
the platform M. By the cooperation of the column-following mode and
the planetary motion mode of FIG. 6, dust and dirt deposited at the
foot of the column can be removed completely.
From the above description, the omni-directional robot cleaner is
featuring in that: (1) Efficient Path Changing Ability: As the
conventional autonomous mobile cleaner is zigzagging, i.e. moving
in a traveling path of stop, turn 90 degrees, move a specific
distance forward, step, turn 90 degrees again, and then move
forward, so as to complete a Z-shaped turn, not only it is time
consuming, but also it will cause the autonomous mobile cleaner to
have blind spot for cleaning. However, the omni-directional robot
cleaner of the invention can continuously change its coordinate of
motion vector directly at a turn or at a location requiring path
change, so that it can perform a smooth S-shaped turn and thus the
efficiency of the omni-directional robot cleaner is greatly
enhanced. (2) Random Motion and Path Change: As a conventional
autonomous mobile cleaner is performing a random motion/path
change, it is required to stop and reactivate at some point that
the whole traveling path is not fluent and will waste a lot of time
in the stopping and the reactivating. However, the omni-directional
robot cleaner of the invention can continuously change its
coordinate of motion vector directly at a turn, so that it can
change its moving direction directly for proceeding to a random
direction and thus the efficiency of the omni-directional robot
cleaner is greatly enhanced.
It is noted that although the omni-directional wheel and the
autonomous mobile cleaner are respectively known to those skilled
in the art, there is no application that integrates
omni-directional wheels in any autonomous mobile cleaner. By
replacing the common wheels with omni-directional wheel while
configuring a sensing unit, a processing unit and a power unit in
the platform of the omni-directional robot cleaner of the
invention, the omni-directional robot cleaner is free from the
shortcomings of those conventional autonomous cleaner, such as poor
maneuverability, poor mobility and insufficient degree-of-freedom
regarding to the driving of the cleaner. Therefore, not only the
operation mobility of the robotic cleaner is enhanced, but also the
moving agility of the same is greatly improved.
While the preferred embodiment of the invention has been set forth
for the purpose of disclosure, modifications of the disclosed
embodiment of the invention as well as other embodiments thereof
may occur to those skilled in the art. Accordingly, the appended
claims are intended to cover all embodiments which do not depart
from the spirit and scope of the invention.
* * * * *